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author | Dave Chapman <dave@dchapman.com> | 2009-05-09 01:04:20 +0000 |
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committer | Dave Chapman <dave@dchapman.com> | 2009-05-09 01:04:20 +0000 |
commit | 69db01e72f2de91d35703919bfc9d0700df83e85 (patch) | |
tree | 18a8d01dc3df13c5dc51b813d7ce70e6bec79704 /apps/codecs/libcook/mdct.c | |
parent | 681a774472eded71f7a82fbfa4c3591f3f98d209 (diff) | |
download | rockbox-69db01e72f2de91d35703919bfc9d0700df83e85.tar.gz rockbox-69db01e72f2de91d35703919bfc9d0700df83e85.zip |
Initial commit of the minimal set of ffmpeg (r18079) files required for Cook (realaudio) decoding. These are the unmodified versions from ffmpeg, committed as a base for future changes.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@20882 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'apps/codecs/libcook/mdct.c')
-rw-r--r-- | apps/codecs/libcook/mdct.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/apps/codecs/libcook/mdct.c b/apps/codecs/libcook/mdct.c new file mode 100644 index 0000000000..cb3388f6ff --- /dev/null +++ b/apps/codecs/libcook/mdct.c | |||
@@ -0,0 +1,229 @@ | |||
1 | /* | ||
2 | * MDCT/IMDCT transforms | ||
3 | * Copyright (c) 2002 Fabrice Bellard | ||
4 | * | ||
5 | * This file is part of FFmpeg. | ||
6 | * | ||
7 | * FFmpeg is free software; you can redistribute it and/or | ||
8 | * modify it under the terms of the GNU Lesser General Public | ||
9 | * License as published by the Free Software Foundation; either | ||
10 | * version 2.1 of the License, or (at your option) any later version. | ||
11 | * | ||
12 | * FFmpeg is distributed in the hope that it will be useful, | ||
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
15 | * Lesser General Public License for more details. | ||
16 | * | ||
17 | * You should have received a copy of the GNU Lesser General Public | ||
18 | * License along with FFmpeg; if not, write to the Free Software | ||
19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
20 | */ | ||
21 | #include "dsputil.h" | ||
22 | |||
23 | /** | ||
24 | * @file libavcodec/mdct.c | ||
25 | * MDCT/IMDCT transforms. | ||
26 | */ | ||
27 | |||
28 | // Generate a Kaiser-Bessel Derived Window. | ||
29 | #define BESSEL_I0_ITER 50 // default: 50 iterations of Bessel I0 approximation | ||
30 | av_cold void ff_kbd_window_init(float *window, float alpha, int n) | ||
31 | { | ||
32 | int i, j; | ||
33 | double sum = 0.0, bessel, tmp; | ||
34 | double local_window[n]; | ||
35 | double alpha2 = (alpha * M_PI / n) * (alpha * M_PI / n); | ||
36 | |||
37 | for (i = 0; i < n; i++) { | ||
38 | tmp = i * (n - i) * alpha2; | ||
39 | bessel = 1.0; | ||
40 | for (j = BESSEL_I0_ITER; j > 0; j--) | ||
41 | bessel = bessel * tmp / (j * j) + 1; | ||
42 | sum += bessel; | ||
43 | local_window[i] = sum; | ||
44 | } | ||
45 | |||
46 | sum++; | ||
47 | for (i = 0; i < n; i++) | ||
48 | window[i] = sqrt(local_window[i] / sum); | ||
49 | } | ||
50 | |||
51 | DECLARE_ALIGNED(16, float, ff_sine_128 [ 128]); | ||
52 | DECLARE_ALIGNED(16, float, ff_sine_256 [ 256]); | ||
53 | DECLARE_ALIGNED(16, float, ff_sine_512 [ 512]); | ||
54 | DECLARE_ALIGNED(16, float, ff_sine_1024[1024]); | ||
55 | DECLARE_ALIGNED(16, float, ff_sine_2048[2048]); | ||
56 | DECLARE_ALIGNED(16, float, ff_sine_4096[4096]); | ||
57 | float *ff_sine_windows[6] = { | ||
58 | ff_sine_128, ff_sine_256, ff_sine_512, ff_sine_1024, ff_sine_2048, ff_sine_4096 | ||
59 | }; | ||
60 | |||
61 | // Generate a sine window. | ||
62 | av_cold void ff_sine_window_init(float *window, int n) { | ||
63 | int i; | ||
64 | for(i = 0; i < n; i++) | ||
65 | window[i] = sinf((i + 0.5) * (M_PI / (2.0 * n))); | ||
66 | } | ||
67 | |||
68 | /** | ||
69 | * init MDCT or IMDCT computation. | ||
70 | */ | ||
71 | av_cold int ff_mdct_init(MDCTContext *s, int nbits, int inverse) | ||
72 | { | ||
73 | int n, n4, i; | ||
74 | double alpha; | ||
75 | |||
76 | memset(s, 0, sizeof(*s)); | ||
77 | n = 1 << nbits; | ||
78 | s->nbits = nbits; | ||
79 | s->n = n; | ||
80 | n4 = n >> 2; | ||
81 | s->tcos = av_malloc(n4 * sizeof(FFTSample)); | ||
82 | if (!s->tcos) | ||
83 | goto fail; | ||
84 | s->tsin = av_malloc(n4 * sizeof(FFTSample)); | ||
85 | if (!s->tsin) | ||
86 | goto fail; | ||
87 | |||
88 | for(i=0;i<n4;i++) { | ||
89 | alpha = 2 * M_PI * (i + 1.0 / 8.0) / n; | ||
90 | s->tcos[i] = -cos(alpha); | ||
91 | s->tsin[i] = -sin(alpha); | ||
92 | } | ||
93 | if (ff_fft_init(&s->fft, s->nbits - 2, inverse) < 0) | ||
94 | goto fail; | ||
95 | return 0; | ||
96 | fail: | ||
97 | av_freep(&s->tcos); | ||
98 | av_freep(&s->tsin); | ||
99 | return -1; | ||
100 | } | ||
101 | |||
102 | /* complex multiplication: p = a * b */ | ||
103 | #define CMUL(pre, pim, are, aim, bre, bim) \ | ||
104 | {\ | ||
105 | FFTSample _are = (are);\ | ||
106 | FFTSample _aim = (aim);\ | ||
107 | FFTSample _bre = (bre);\ | ||
108 | FFTSample _bim = (bim);\ | ||
109 | (pre) = _are * _bre - _aim * _bim;\ | ||
110 | (pim) = _are * _bim + _aim * _bre;\ | ||
111 | } | ||
112 | |||
113 | /** | ||
114 | * Compute the middle half of the inverse MDCT of size N = 2^nbits, | ||
115 | * thus excluding the parts that can be derived by symmetry | ||
116 | * @param output N/2 samples | ||
117 | * @param input N/2 samples | ||
118 | */ | ||
119 | void ff_imdct_half_c(MDCTContext *s, FFTSample *output, const FFTSample *input) | ||
120 | { | ||
121 | int k, n8, n4, n2, n, j; | ||
122 | const uint16_t *revtab = s->fft.revtab; | ||
123 | const FFTSample *tcos = s->tcos; | ||
124 | const FFTSample *tsin = s->tsin; | ||
125 | const FFTSample *in1, *in2; | ||
126 | FFTComplex *z = (FFTComplex *)output; | ||
127 | |||
128 | n = 1 << s->nbits; | ||
129 | n2 = n >> 1; | ||
130 | n4 = n >> 2; | ||
131 | n8 = n >> 3; | ||
132 | |||
133 | /* pre rotation */ | ||
134 | in1 = input; | ||
135 | in2 = input + n2 - 1; | ||
136 | for(k = 0; k < n4; k++) { | ||
137 | j=revtab[k]; | ||
138 | CMUL(z[j].re, z[j].im, *in2, *in1, tcos[k], tsin[k]); | ||
139 | in1 += 2; | ||
140 | in2 -= 2; | ||
141 | } | ||
142 | ff_fft_calc(&s->fft, z); | ||
143 | |||
144 | /* post rotation + reordering */ | ||
145 | output += n4; | ||
146 | for(k = 0; k < n8; k++) { | ||
147 | FFTSample r0, i0, r1, i1; | ||
148 | CMUL(r0, i1, z[n8-k-1].im, z[n8-k-1].re, tsin[n8-k-1], tcos[n8-k-1]); | ||
149 | CMUL(r1, i0, z[n8+k ].im, z[n8+k ].re, tsin[n8+k ], tcos[n8+k ]); | ||
150 | z[n8-k-1].re = r0; | ||
151 | z[n8-k-1].im = i0; | ||
152 | z[n8+k ].re = r1; | ||
153 | z[n8+k ].im = i1; | ||
154 | } | ||
155 | } | ||
156 | |||
157 | /** | ||
158 | * Compute inverse MDCT of size N = 2^nbits | ||
159 | * @param output N samples | ||
160 | * @param input N/2 samples | ||
161 | */ | ||
162 | void ff_imdct_calc_c(MDCTContext *s, FFTSample *output, const FFTSample *input) | ||
163 | { | ||
164 | int k; | ||
165 | int n = 1 << s->nbits; | ||
166 | int n2 = n >> 1; | ||
167 | int n4 = n >> 2; | ||
168 | |||
169 | ff_imdct_half_c(s, output+n4, input); | ||
170 | |||
171 | for(k = 0; k < n4; k++) { | ||
172 | output[k] = -output[n2-k-1]; | ||
173 | output[n-k-1] = output[n2+k]; | ||
174 | } | ||
175 | } | ||
176 | |||
177 | /** | ||
178 | * Compute MDCT of size N = 2^nbits | ||
179 | * @param input N samples | ||
180 | * @param out N/2 samples | ||
181 | */ | ||
182 | void ff_mdct_calc(MDCTContext *s, FFTSample *out, const FFTSample *input) | ||
183 | { | ||
184 | int i, j, n, n8, n4, n2, n3; | ||
185 | FFTSample re, im; | ||
186 | const uint16_t *revtab = s->fft.revtab; | ||
187 | const FFTSample *tcos = s->tcos; | ||
188 | const FFTSample *tsin = s->tsin; | ||
189 | FFTComplex *x = (FFTComplex *)out; | ||
190 | |||
191 | n = 1 << s->nbits; | ||
192 | n2 = n >> 1; | ||
193 | n4 = n >> 2; | ||
194 | n8 = n >> 3; | ||
195 | n3 = 3 * n4; | ||
196 | |||
197 | /* pre rotation */ | ||
198 | for(i=0;i<n8;i++) { | ||
199 | re = -input[2*i+3*n4] - input[n3-1-2*i]; | ||
200 | im = -input[n4+2*i] + input[n4-1-2*i]; | ||
201 | j = revtab[i]; | ||
202 | CMUL(x[j].re, x[j].im, re, im, -tcos[i], tsin[i]); | ||
203 | |||
204 | re = input[2*i] - input[n2-1-2*i]; | ||
205 | im = -(input[n2+2*i] + input[n-1-2*i]); | ||
206 | j = revtab[n8 + i]; | ||
207 | CMUL(x[j].re, x[j].im, re, im, -tcos[n8 + i], tsin[n8 + i]); | ||
208 | } | ||
209 | |||
210 | ff_fft_calc(&s->fft, x); | ||
211 | |||
212 | /* post rotation */ | ||
213 | for(i=0;i<n8;i++) { | ||
214 | FFTSample r0, i0, r1, i1; | ||
215 | CMUL(i1, r0, x[n8-i-1].re, x[n8-i-1].im, -tsin[n8-i-1], -tcos[n8-i-1]); | ||
216 | CMUL(i0, r1, x[n8+i ].re, x[n8+i ].im, -tsin[n8+i ], -tcos[n8+i ]); | ||
217 | x[n8-i-1].re = r0; | ||
218 | x[n8-i-1].im = i0; | ||
219 | x[n8+i ].re = r1; | ||
220 | x[n8+i ].im = i1; | ||
221 | } | ||
222 | } | ||
223 | |||
224 | av_cold void ff_mdct_end(MDCTContext *s) | ||
225 | { | ||
226 | av_freep(&s->tcos); | ||
227 | av_freep(&s->tsin); | ||
228 | ff_fft_end(&s->fft); | ||
229 | } | ||